1. Field of the Invention
The invention relates to the metallurgical field, and more particularly to a method and a device for extracting and enriching lithium.
2. Description of the Related Art
Lithium exists in nature in the form of ore and brine. Most lithium exists in brine, and especially in salt lake brine, the reserve of which is more than 80% of the total reserve. However, with the rapidly growing market demands, the lithium from the ore cannot meet the demands, and the exploration cost is very high. Recently, more and more attention has been aroused to lithium in the salt lake brine. The brine usually includes chlorides, sulfates, and carbonates of sodium, potassium, magnesium, calcium, boron, and lithium. In addition to rare salt lakes having a low ratio of magnesium to lithium (6:1), in most salt lake brine, the ratio of magnesium to lithium is higher than 40, and the ratio is even higher than 1800 in some salt lakes. Lithium coexists with a large amount of alkaline-earth metals. In accordance with the diagonal rule, the chemical property of Mg2+ is very similar to that of Li+, so that the separation of the lithium from the magnesium is very difficult, the extraction cost of lithium has been largely increased, which restricts the extraction and application of lithium. Methods such as precipitation, carbonization, ion exchange, and solvent extraction have been applied to solve the technical problem and find a way to effectively explore lithium recourse in brine. However, most of these methods have complicate process, high cost, strong corrosion to the device, low product purity, and is inconvenient for mass production.